Depending on whether or not you can fulfil what is asked of you, being an Apple supplier sounds like it’s either the best or worst experience imaginable.

In the wake of the crashing and burning of Apple’s former sapphire supplier GT Advanced Technologies, some of Cupertino’s other contractors have pitched in with their take; filling the Wall Street Journal in on a few of the lessons they’ve learned along their roller coaster rides with Apple.

The two biggest take-homes? Don’t make promises you can’t keep, and don’t rely too much on Cupertino.